Wheel balancer



s E M L O H G H WHEEL BALANCER Filed Feb. 19, 1941 5 Sheets-Sheet l HERBERT a HOL MES W H. G. HOLMES WHEEL BALANCER Filed Feb. 19, 1941 5 Sheets-Shae 5 HERBERT 6' HOL M55 atent 23v 1944 OER Herbert G. Holmes, Lansing, Mich, assignor to Food Machinery Corporation, San .iose, Caiif., a corporation of Delaware Application February 19, 1941, Serial No. 379,580,

24 Claims.

In order to obtain safe and smooth-runnin operation of an automobile wheel at high speed it is essential that the wheel be accurately balanced, for even a slight amount of unbalanced weight will set up undesirable vibrations and, in the case of front wheels, dangerously erratic forces that may tend to impair the driver's control of the vehicle.

An object of this invention is to provide a machine upon which the wheel may be mounted and which will then enable an operator to determine whether the wheel is correctly balanced.

Another object of the invention is to provide a machine on which both the static and dynamic balance of the wheel may be tested.

A further object is to provide a wheel balancer with improved means for locating unbalanced weight in a wheel.

Another object is to provide a wheel balancer with improved means for testing a wheel for dynamic balance and for indicating the location and amount of any existing unbalanced weight.

Other objects will be evident after the following disclosure of a. machine in which the invention is embodied.

In the drawings:

Fig. 1 is a side elevation of the machine showing the wheel mounted thereon and positioned with its axis upright.

Fig. 2 is a similar view with the wheel positioned with its axis horizontal. pedestal has been broken away to disclose mechanism within.

Fig. 3 is an enlarged fragmentary vertical section of Fig. 1.

Fig, 4 is an enlarged fragmentary section taken a indicated by the arrows 4-4 in Fig. 3.

Fig. 5 is a view similar to Fig. 3 with the wheel positioned with its axis horizontal.

Fig. 6 is a horizontal section taken as indicated by the arrows 86 in Fig. 1.

Fig. '7 is a vertical section taken as indicated by the arrows 1-1 in Fig. 3.

Fig. 8 is an enlarged fragmentary view taken as indicated by the arrows 8-8 in Fig. 2.

Fig. 9 is a perspective view showing the mechanism located under the wheel at the top of the pedestal.

Fig. 10 is a fragmentary section taken as indicated by the arrows Iii-W in Fig. 6.

Fig. 11 is a. perspective View of the wheel in position for the static balance test.

In general the testing machine comprises a pedestal (Fig. 1) which provides the frame for supporting the instrumentalities by means of which the static and dynamic balance of an automobile wheel, such as 2|, may be determined.

Part 01 the One of the features of this machine is that the wheel H is positioned with its axis upright, as shown in Fig. 1, during part of the testing operation, and with its axis horizontal, as shown in Fig. 2, during other parts of the testing operation without removing the wheel from the machine.

The supporting frame will now be described in detail. The pedestal 20 (Fig. 2) comprises a base casting 22 which is adapted to rest upon the fioor. The'base casting 22 has a well 23 formed therein which receives the foot of a hollow column 24 which is rigidly secured therein. A casting 25 (Fig. 3) has a horizontal flange 26 which rests upon the top edge of the column 24 and has a vertical depending flange 21 which fits within the walls of the column. The casting 25 (Fig. '7) is securely held in place in the top of the column.

Two vertical rods 28, 29 have their upper ends secured in the casting 25 at 30 and ti, respectively. The lower ends of the rods 28, 29 project downwardly through apertures in the bottom 32 of the well 23 (Fig. 2) and the projecting ends are threaded to receive nuts, such as 33. A casting 35 (Figs. 1 and 2) fits on top of the column 24 and has a laterally extending arm 38. As can be seen in Fig. 3, the casting 35 has a skirt 38 which encompasses the column 24 and a shoulder 89 which rests on the upper face of the flange 28 of the casting 25.

An adjustable support, indicated generally at 40 (Figs. 3 and 5) is mounted in the frame of the machine for swinging movement. The support 40 comprises an arbor ll rigidly mounted in a trunnion 42 intermediate the ends of the arbor so that a portion 43 of the arbor extends on one side of the trunnion 42 and another portion it extends on the other side.

The trunnion i2 is mounted for rotation in the frame by means of stub shafts i5, 88 (Fig, 7)

forming part of the trunnion and received in bearings 41, 8. The lower halve i9, 50 of the bearings are formed integrally with the casting 25, while the upperhalves M, 52 are removable caps attached to the lower halves by. cap screws 53 and studs 5%, provided with nuts 57.

Preferably the stub shafts M5 and 46 are fitted with thin bushings Ma and "a respectively, made of Bakelite or fibre. These bushings are slotted along oneside, as at 45b and 46b, so as to enable them to be contracted slightly when the bearing caps 5i and 52 are screwed down tight, and exert considerable friction on the stub shafts so that while the arbor ii can be readily shifted by hand from vertical to horizontal position and vice versa, it is not free -to do so unless some force is exerted on it. The slots 45b and Mb in the bushings also permit compensation for wear which may be accomplished by screwing down the bearing caps BI and 52 to tighten up the bushings.

As can be seen in Fig. 3, the cap SI the bearing 41 is secured to the lower half 40 of the bearing by the cap screw 50 and the stud 00 and nut 51. The cap of the bearing ior stub shaft 40 is similarly attached. The stud 55 (Fig. 5) projects upwardly through an aperture in the casting 35 and a nut 50 is threaded on the stud 05 to hold the casting in place with its shoulder 00 on the flange 20 of casting 20 and its skirt 00 encompassing column 24. Both studs 50 (Fig. 7) project up through the casting 05 and are provided with nuts 50 (Fig. 6).

It will be understood that the arbor 4I does not rotate upon its axis, being fixed in the trunnion 42 by means of which it is mounted for swinging movement about the axis of stub shafts 40, 40 through ninety degrees from the vertical position shown in Fig. 3 to the horizontal position shown in Fig. 5. A slot 00 (Fig. 9) is formed in the casting 05 to permit the above-described movement of the arbor H which projects therethrough.

Means disposed in the pedestal are provided for facilitating and controlling the movement of the arbor from one adjusted position to the other and for securing it in the selected position of operation. Referring to Figs. 3, 5, and 7, a cross head 10 is slidably mounted on the rods 20. 20 by means of ears II, 12 having aligned apertures through which the rod 20 passes, and ears 10, I4 having aligned apertures through which the rod 20 passes. Compression springs 10,10 encompassing the rods 20, 20, respectively, are interposed between the cross-head I0 and the bottom of the casting 25. The crosshead is connected to the portion 44 oi the arbor 4| by double links 00, attached by means of a pin 0i to a lug 02 secured to the arbor H, and attached by means of a pin 00 to an car 04 formed on the cross-head I0.

A latch 00 (Figs. 3 and I5) is provided for hold ing the arbor H in either horizontal or vertical position. The latch is connected by means or a pin 0| to the projecting end 44 or the arbor 4I. A slot 02 is formed in the latch. A pin 00 having its ends secured in cars 04 formed on the column 24, passes through the slot 02. When the arbor H is in the horizontal position shown in Fig. 5 the pin 00 is in the end of the slot 02. A recess 00 communicating with the slot 02 is formed in the latch 00 to receive the pin 00 when the arbor 4I is in the vertical position shown in Fig. 3. A leaf spring 00 secured to the latch 00 at 01 engages the arbor H to insure the seating of the pin 00 in the recess 05 and to resiliently maintain the latch in engagement with the pin when the arbor is in the vertical position.

Means are provided for releasing the latch to permit the arbor to be swung to the horizontal position. A push rod I00 is supported for vertical movement in a bracket IOI secured inside the wall or the column 24 by screws I02. The push rod passes through apertures formed in the horizontally-extending end portions of the bracket as shown at I00 (Fig. 3) and at I04 (Fig. 2). The push rod I00 is operated by a pedal I05 adjustably secured to a lever I00 by a set screw I01. The lever I00 passes through an aperture I00 in the wall of the well 20 and the bottom 01' this aperture is used as a fulcrum when the pedal is depressed to elevate the inner end of the lever I00 which is pivotally attached at I00 to a clevis IIO secured to the end oi. the push rod I00. A compression spring II2 interposed between the clevis H0 and the bracket IOI urges the push rod downwardly and lifts the pedal I05 after it has been depressed. When the operator steps on the pedal I00 the push rod I00 engages the latch 00 (Fig. 3) and lifts it on the pin 00, thus releasing the arbor H for swinging on its trunnion.

It will be understood that in operation the horizontal position of the arbor H as shown in Fig. 5 is maintained by the weight of the wheel being supported thereby, the springs I0 and I0 being of such size as to readily yield under the weight oi the wheel so as to permit the arbor to assume this position. At the same time it should be noted that the springs 15 and I0 are sumcientiy strong so that when no wheel is mounted on the arbor and the latch is in released position, they elevate the arbor to an angle of about 45 degrees, that is to say, about midway between its vertical and horizontal positions. This is advantageous in that it makes it easier for the operator to mount a heavy wheel accurately on the arbor, than it would be if he had to mount the wheel on the arbor in either its vertical or horizontal positions.

This arrangement is particularly helpful to the operator when the wheel has to be mounted on a face plate in which case the holes in the wheel have to be placed in register with the holes in the face plate for attachment thereto. The face plate method of mounting wheels has not been disclosed herein because it was deemed to be wellknown in the art and is disclosed in the patent to Morse, 2,136,633, issued November 15, 1938.

A spindle I20 (Fig. 3) is supported on the arbor H. The outer end of the spindle is threaded at I2I to receive a nut I22. The inner end of the spindle is formed as a hollow cylindrical quill I20 having an external shoulder I24 and a counterbore I25. The spindle is supported on the arbor by a self-aligning ball bearing I00. The outer race III 01' the bearing is fitted into the quill I20. The inner race I02 is carried on the end I30 of the arbor H which is reduced in diameter to form a shoulder I34 against which the race is held by a retaining washer and screw I00. Two annular rows of balls are disposed between the inner and outer races and the ball-engaging sur-. face or the outer race is spherical to permit the spindle to tilt on the arbor as well as to rotate thereon.

A second bearing I40 is provided for confining the spindle to rotation when in the horizontal position (Fig. 5). The outer race ill of the bearing I40 fits in the counterbore I25 of the quill I20.

The inner race I42 is carried on the projecting end of a bushing I40 which is secured in the hub I44 of an arm I45. The bushing I40 has a sliding fit on the portion 40 or the arbor 4|. A collar I40 is secured to the arbor 4I and a compression spring I" is interposed between the collar and the end of the bushing I40 to urge the bushing to the right in Fig. 5 and withdraw the bearing I40 from the counterbore I25 when the arbor 4i -is swung to the vertical position (Fig. 3) so that in this position the spindle I20 is supported solely by the bearing I30 which permits it to tilt.

Means are provided for positively inserting the bearing I40 in the counterbore I20 as the arbor 4| is moving down to the horizontal position. The inner end or the hub I44 is always in engagement with the casting 35. The margins I50, I5I (Figs. 6 and 9) oi the slot 60 are raised to form a cam track on which the hub slides as the arbor H is swung from one position to the other. The hub is prevented from turning by guide pins I52, I50 mounted on the hub and engaging the walls 01' the slot 80. The slot and its margins are disposed eccentrically with respect to the axis of the trunnion 42. As viewed in Fig. 3, the distance from the axis of trunnion shall; it to the lace oi the hub I is less than the distance between these two points when the parts are in theposition shown in Fig. 5.

In other words, the margins I", iii of the slot t2 act as a cam to slide the bushing I42 outwardly on the arbor ll when it is swung down to the horizontal position, thus automatically introducing the hearing I" into the counterbore I25 to prevent the spindle from tilting and to confine it to rotation on a horizontal axis. Conversely, when the arbor is swung up to the vertical position this construction permits the spring It! to remove the bearing Ill so that the spindle is tree to tilt on the bearing I.

The spindle I2. is adapted to have a wheel mounted thereon for testing. A collar I" (Fig. 3) fits on the quill I23 against the shoulder I24. and a cone IOI is provided for the reception of the wheel. The cone "I has an aperture I82 in the end through which the spindle passes. It also has an internal flange I which engages the exterior of the quill I21 and a downwardly projecting flange I which engages the collar I80. Preferably the cone is held in place by a light press fit with the spindle and quill.

The wheel II with the tire I'll thereon is placed on the spindle with the outer race I12 of the inner wheel bearing seated on the cone lil. A cone lli having a bore I" which fits the spindle I122 is slid on to seat in the outer race I" of the outer wheel bearing. The nut I22 is then screwed onto the threaded portion I2I of the spindle and serves to clamp the wheel onto the spindle with its axis in alignment with the axis of the spindle by reason of the centering cones ISI, lit. The wheel and spindle will thereafter move in unison as an integral body.

In order to spin the wheel when th arbor is in the upright position a motor IIII (Figs. 1 and '6) is provided. The motor is attached to a bracket Ill having a pin I82 secured in ears "3,184 formed in the bracket. The pin I82 is rotatable in an apertured boss ll! formed in the end of the arm II which is inte ral with the frame castin til. A handle III is attached to the bracket "I which the operator grasps to swing th bracket on its pivot pin I82 to engage the driving wheel m of the motor In with the periphery m (Fig. 6) of the tire. To enable the operator to stop the automobile wheel 2i from spinning a brake shoe II! is secured to the bracket Iii. This shoe can be brought into frictional engagement with the tire by swinging the bracket around to the broken line position shown in Fig. 6.

A wobble plate I" (Fig. 3) is carried by the collar I". The plate has a hub Ill which freely encom the collar but is frictionally held in place thereon by a series of leaf springs. I92 secured inside the hub Isl an bearing against a spherical surface I formed on the collar. In this manner the wobble plate is mounted for un versal tilting movement on the collar, but will be held in any adjusted position by the friction of the leaf springs I92 on the collar. The periphery of the plate is provided with a scale I83 (Fig. 2;) which encompasses it and is graduated. preferably in 5 units, and divided in half, so that there are two successive scales, each covering 180 of the periphery of m 0 to 36. il'he wobble plate m is adapted to be adjusted so that it will run true while the wheel 2| is the plate and each reading.

spinning, even though the wheel may gyrate or wobble due to dynamic unbalance. A lever lat (Figs. 1 and 6) having a handle I98 is secured to the end of a shaft l9! rotatably mounted in the casting 3B. The lever I95 has an upwardly inclined arm I98 which carries a disc or button I" held in place by a cap screw I99a. Secured to the other end of the shaft i9! and disposed parallel to the arm I98 is another arm 2" having a disc or button 2M secured thereto by cap screw 20m. The buttons I98 and 2M are identical in size and are disposed with their axes in alignment, but, as best seen in Figs. 1 and 2, the discs are eccentrically mounted on their respective cap screws so that they may be adjusted for proper height and locked in position by the cap screws.

The operator may grasp the handle I96 and depress the lever I to raise the discs I99, 2M into engagement with the plate I while it is spinning in unison with the wheel. The pressure of the discs on the plate adjusts it to run true-that is to say, in a single plane without any wobble. As will presently be explained, the axis 203 of the spindle I20, during rotation with a wheel thereon, will not be coincident with the true vertical 202 if the wheel is dynamically unbalanced, but will assume a gyratory motion, in which event the plate ISO is adjusted relative to the collar I", this being possible on account of the frictional engagement of the springs W2 with the collar.

when the handle I96 is released the lever W5 is rotated counterclockwise (Fig. l) to lower the discs away from the plate. The lever has a pin 2" (Fig. 10) secured thereto which projects through a slot 2 in the arm 36 of the casting 85. A leaf spring 2I2 bent in a U shape is secured at one end to a lug 2I3 iormed integrally with the casting by a set screw 2 threaded into the lug and provided with an adjustment lock nut Iii. The free end 2W of the spring bears upwardly against the pin 2Ill to lift the arm I95. The set screw is adjusted so that its tip 2|! acts as a limit stop which the end m of the spring engages when the lever I is depressed, and thus serves to determine the extent of elevation of the discs I, 20!. Preferably, as shown in Figs. 1 and 6, the common axis 205 of these discs is offset from, and lies outside the plane of, the vertical axis 202 of the plate I90. By employing these two oflset discs the plate can be accurately and dependably leveled by depressing the lever I".

When the spindle I20 (Fig. 2) is swung to the horizontal position, an indicator means, indicated generally at 220, is automatically disposed in cooperative relation with the wobble plate ltd. It will be recalled that the arbor ll (Fig. 3) has slidably mounted thereon the hub Mt of an arm I45. The hub and arm occupy the position shown in Fig. 3 when the arbor is in the vertical position.

A, pointer 22I is pivotally mounted on the arm I at 222. The pointer is urged upwardly by a wire spring 223 coiled about the pivot 222. The

ends 224, 225 project outwardly from the pivot.

The lower end 224 (Figs. 3 and 4) is anchored in a lug 222 formed integrally with the arm M5. The upper end 225 underlies and bears upwardly against a flange 221 formed on the pointer 22L An indicator pin 2% (Figs. 3 and 4) having a button head =23l is slidably mounted in a boss 232 formedintegrally with the arm I45. A spring 232 coiled about the pin 231i and. bearing against the under side of the boss 232 urges the pin downwardly in Fig. 4 to maintain the end 234 of the pin in engagement with a flange 235 on the pointer 22!.

The arm I45 has a pad 238 (Fig. 6) formed at the end thereo for supporting a plate 239 (Fig. 8) having a scale 240 marked thereon. The pointer 22! projects through a slot 24! in the plate and is provided with an indicator 242 which cooperates ith the scale 240. The scale is graduated on eit er side of the zero point to indicate units of weight to be added to the inside and the outside of the automobile wheel. It will be noted in Fig. 8 that the plate 239 has inscriptions thereon which designate the left and right positions of the scale 240 as inside and outside. respectively. The scale plate 239 is adjustably mounted on the pad 238 by means of four pins 2 which pass through slots 245 in the plate 239 and are secured in the pad 233.

In the position of the parts of the indicator means 220 shown in Fig. 3 the pointer 22! under the influence of the spring 223 is swung upwardly, its upward movement being limited by the engagement of the end of the pointer in the end of the slot in the scale plate 239. The indicator pin 230, however. does not engage the wobble plate I90 because the arm I 45 is removed therefrom by withdrawal of its hub I H and bearing I40 from the spindle counterbore I25, as previously explained. The indicator means 220 is thus inoperative when the arbor is vertical.

When the arbor is swung down to the horizontal position (Fig. 5) the hub I, in moving toward the spindle to insert the bearing M in the counterbore, also moves the indicator means 220 toward the wobble plate I90. A cam 250 is secured to a counter shaft 25! rotatably mounted in the arm I45 which has a boss 252 (Fig. 4) formed therein to provide adequate bearing for the shaft. A counterweight 253 is secured to the opposite end of the shaft 25!. The cam 250 is adapted to engage the flange 22! of the pointer. When the arbor is upright the cam 250 is disposed as shown, but when the arbor is swung down the counterweight 253 turns the cam 250 clockwise with respect to the arm I45 bringing it into engagement with the flange 22! and moving the pointer 22I clockwise on its pivot 222 to the position shown in Fig. 5. The indicator pin 230 under the influence of its spring 233 (Fig. 4) follows the pointer 22! and withdraws from the plate I90.

When the arbor is in the horizontal position shown in Fig. 5 the counterweight 253 may be manually lifted to turn the cam 250 through onehundred-eighty degrees to the position shown in Figs. 2 and 8. In this manner the pointer 22! can be released to the influence of its spring 223 which causes the indicator pin 230 to be projected toward the wobble plate I90 so that the head 23! of the pin engages an annular surface 255 formed on the face of the plate. The automobile wheel 2! can now be manually turned, the wobble plate I90 turning therewith. If the plate is tilted on the collar I60 the pin 230 will reciprocate as its head 23I follows the surface of the. Wobble plate I90. This movement of the indicator pin will be communicated to the pointer 22!, and the movement of its indicator 242 (Fig. 8) over the scale 255 may be observed in connection with the position of the indicator pin 230 with respect to the scale I93 on the periphery of the wobble plate I90.

of about 45 degrees intermediatethe vertical and horizontal positions shown in Figs. 1 and 2, respectively. the springs I5 and I8 serving to maintain it in this position until the wheel is mounted on the spindle. Upon placing the wheel on the spindle its weight swings the arbor into horizontal position as shown in Figs. 2 and 5, and the wheel is then secured on the spindle as previously described by tightening the nut I22.

The springs I5, I6 (Figs. 5 and 7) are compressed by the upward movement of the cross head I0 when the arbor is lowered and serve to cushion the descent of the wheel assembly and prevent sufficient shock to spring the arbor, or otherwise injure the machine. The frictional grip of the bushings 45a and 46a also assists the springs in cushioning the shock when the wheel assembly is lowered into horizontal position.

With the wheel and arbor now in the position shown in Fig. 5, the wheel and spindle assembly is supported for free rotation on a horizontal axis by the bearings I30 and I I0, and if the wheel is statically unbalanced it will rotate until its heaviest portion comes to rest at the bottom of the wheel. After the wheel has come to rest a chalk mark 250 (Fig. 11) is made on the inner side wall of the tire III opposite the slot 24! in the indicator plate 239. The mark 260 will be one-hundred-eighty degrees from the heavy spot in the wheel. A balance wheel 235 (Fig. 5) of well-known construction is now placed on the rim of the wheel at the chalk mark. The wheel is then manually turned ninety degrees and released. If the wheel turns it is not yet balanced. If the balance weight goes up it is too light and a heavier weight should be substituted. If the balance weight goes down it is too heavy and a lighter weight should be used. If the wheel cannot be balanced by using one weight, two weights of equal size are placed equal distances on each side of the chalk mark and moved around until the wheel is statically balanced. When the wheel will rest in any position it is statically balanced.

The operator then swings the wheel and arbor to the upright position (Fig. 1) where it is retained by the latch 90. The wheel is then rotated at high speed by starting the electric motor I and engaging its drive wheel I8! with the tread of the tire. The bracket I8! is then swung away to disengage the driving wheel I81 from the tire allowing the wheel undergoing test to spin freely.

It will be recalled that in this position the spindle I20 is supported solely by the spherical bearing I30 (Fig. 3) so that as the wheel spins the spindle is free to gyrate if the wheel is dynamically unbalanced. When this occurs the spindle axis 203 (Fig. 1) generates an inverted cone and the upper end of the spindle makes one circuit of the base of the cone each time the wheel makes a revolution. The operator now depresses the lever I95 to engage the discs I99. 20! with the wobble plate I which is thereby adjusted to remove any wobbling motion from it and to cause it to run true. The lever I is then released and the wheel is brought to a stop by engaging the brake shoe I89 with the tire.

Depressing the pedal I05 to release the latch 90. the operator thereupon lowers the wheel to the position shown in Fig. 2 where the spindle H20 is supported on the bearings I30 and I40 (Fig. 5) with its axis horizontal, the bearing I40 having been automatically inserted in the counterbore- I25 by. the camming action of the slot margins I50, I5I (Fig. 9) on the hub I. If the wheel is dynamically unbalanced the wobble plate I90, as shown in Fig. 2, will now be found to be inclined with respect to the spindle axis, having er 22 I, causing the indicator 242 (Fig. 8) to move back and forth on the scale 240. The scale plate is adjusted relative to the pad 238 by sliding it on the pins 2 until the zero point of the scale 240 is at the mid-point of the travel of the indicator 242. When this adjustment has been made the indicator will move to a position, such as that shown, for example, in full lines in Fig. 8, opposite 2" on the outside end of the scale and then will move back to the broken line position opposite "2". on the "inside end of the scale, these two positions being the limits of movement of the indicator as the wheel is turned.

The wheel is stopped at the maximum ,inside.

position where the indicator 242 is in the broken line position. A balance weight of the size indicated, in this case 2 ounces, is applied to the inside rim of the wheel opposite the slot 242 in the plate. The number on the scale I93 opposite the indicator pin 230 is noted in order to determine the angular position of the weight on the wheel. The operator then turns the wheel one-hundred-eighty degrees as indicated by the indicator pin 230 on the scale I93, or until the same number appears opposite the indicator pin, this being the corresponding number in the second scale. two 180 scales on the plate. Corresponding numbers in these two scales are arranged diametrically opposite to facilitate turning the wheel 180 at this time. A 2-oz. balance weight is then applied to the outside rim of the wheel. In this manner, the wheel is dynamically balanced by placing two equal balance weights exactly one-hundred-eighty degrees apart, one on the inside rim, the other on the outside rim.

The indicator means 220 serves to show the exact points on the wheel that the weights should be applied and also the size of the weights to be used.

It Will be understood that the scale 240 i callbrated for average size and weight wheels and therefore larger and heavier wheels will require slightly heavierbalance weights than indicated on the scale. Conversely, smaller wheels will require the application of slightly lighter weights. In order, therefore, to make certain that the proper size weights have been applied, and that they have been accurately placed, it is advisable to re-check the wheel for dynamic balance by raising the arbor to vertical position again, and repeating the operations of spinning the wheel, and adjusting the wobble plate. When the arbor is again lowered and theindicating means 220 is operated, the pointer 22l should remain at zero, if the wheel is dynamically balanced because in that case the wobble plate Iflt will not be tilted with respect to the spindle when the plate is trued up, on account of the fact that the wheel itself will run true. If the It will be recalled that there arere-check shows that the wheel is still dynamically unbalanced it shows either that the operator applied the wrong size of weights or did not place them accurately, and he may then apply the proper size weights or correct their placement as may be necessary until the test shows that the wheel is properly balanced.

Having thus described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A wheel balancer comprising, a frame, a support mounted in said frame for movement from a vertical to a horizontal position, a spindle adapted to have a wheel mounted thereon, means for mounting said spindle on said support ior rotation and tilting with respect thereto, and means automatically operable upon movement of said support to the horizontal position to prevent said spindle Irom tilting on said support and to confine said spindle to rotation on a horizontal axis.

2. A wheel baiancer comprising, a frame, a support mounted in said frame for movement from a horizontal position to a vertical position and adapted to be secured in either position, a spindle adapted to have a wheel mounted thereon, bearing means for mounting said spindle for rotation and tilting on said support, a second bearing means adapted to engage said spindle when said support is in the horizontal position to prevent tilting of said spindle with respect to said support and confine the spindle to rotation about a horizontal axis, and means automatically operable upon movement or said support to the horizontal position for engaging said second bearing with said spindle.

3. A wheel balancer comprising, a frame, an arbor mounted on a trunnion in said frame for movement about a horizontal axis, a spindle adapted to have a wheel mounted thereon, a bearing on said arbor to support said spindle for universal tilting movement thereon when said arbor is in vertical position, a second bearing movable axially with respect to said arbor and adapted to cooperate with said first bearing in the horizontal position of said arbor to conline said spindle to rotation on a horizontal axis, and means automatically operable upon movement of said arbor to vertical position to render said second bearing inoperative.

4. A wheel balancer comprising, a frame, an arbor mounted on a trunnion in said frame for movement about a horizontal axis, a spindle adapted to have a wheel mounted-thereon, a bearing on said arbor to support said spindle for universal tilting movement thereon when said arbor is in vertical position, a second bearing movable axially with respect to said arbor and adapted to cooperate with said first bearing in the horizontal position of said arbor to confine said spindle to rotation on a horizontal axis, and means actuated by movement of said arbor to horizontal position to move said second bearing to operative position.

5. A wheel balancer comprising, a frame, an arbor mounted on a trunnion in said frame for rotation about a horizontal axis,- means on said 4 rotation about a horizontal axis, means on one end of said arbor for supporting a wheel for rotation, spring means on said frame below the arbor, and pivotally mounted means intermediate said spring means and the other end of the arbor and cooperating with said spring means for cushioning the movement of the arbor to the horizontal position.

7. A wheel balancer comprising a frame, means adapted to have a wheel mounted thereon for testing, means to support said mounting means, said supporting means being adjustable in said frame to position the wheel with its axis upright or horizontal. said supporting means when positioning the wheel with its axis upright permitting the wheel to wobble when it has been set spinning, a member carried by said mounting means to rotate in unison with the wheel and adapted to be tilted with respect thereto, means to engage said member while the wheel is spinning and wobbling to cause said member to run true, means operable when said supporting means is adjusted to position the wheel axis horizontal to indicate the adjustment of said member relative to said mounting means, said indicating means indicating the dynamic unbalance of the wheel, and means automatically operable upon.

movement of said supporting means to position the wheel with its axis upright to render said indicating means inoperable with respect to said member.

8. A wheel balancer comprising a frame, means adapted to have a wheel mounted thereon for testing, means to support said mounting means, said supporting means being adjustable in said frame to position the wheel with its axis upright or horizontal, said supporting means when positioning the wheel with its axis upright permitting the wheel to wobble when it has been set spinning, a member carried by said mounting means to rotate in unison with the wheel and adapted to be tilted with respect thereto, means to engage said member while the wheel is spinning and wobbling to cause said member to run true, said supporting means including an auxiliary means adapted to engage said mounting means to support the wheel for rotation on a horizontal axis, means on said frame to cause said auxiliary supporting means to engage said mounting means upon movement of said supporting means to position the wheel with its axis horizontal, and indicating means on said auxiliary supporting means adapted to cooperate with said member when said auxiliary means is engaged with said mounting means to indicate the amount of wobble of said member when the wheel is turned on a horizontal axis.

9. A wheel balancer comprising a frame, means adapted to have a wheel mounted thereon for testing, means to support said mounting means, said supporting means being adjustable in said frame to position the wheel with its axis, upright or horizontal, said supporting means when positioning the wheel with its axis upright permitting the wheel to wobble when it has been set spinning, a member having a peripheral graduated scale, said member being carried by said.

mounting means to rotate in unison with the wheel and adapted to be tilted with respect thereto, means to engage said member while the wheel is spinning and wobbling to cause said member to run true, said supporting means including an auxiliary means adapted to engage said mounting means to support the wheel for rotation on a horizontal axis, means on said frame to cause said auxiliary supporting means to engage said mounting means upon movement of said supporting means to position the wheel with its axis horizontal, indicating means on said auxiliary supporting means adapted to cooperate with said member when saidauxiliary means is engaged with said mounting means, said indicating means including a contact to engage said member and movable in response to the wobble thereof when the wheel is turned, a pointer actuated by said contact, and a scale cooperating with said pointer, the dynamic unbalance of the wheel being indicated in amount by said pointer on said pointer scale and in location by the corresponding position of said contact with respect to said peripheral scale on said member.

10. A wheel balancer comprising a frame, means adapted to have a wheel mounted thereon for testing, means to support said mounting means, said supporting means being adjustable in said frame to position the wheel with its axis upright or horizontal, said supporting means when positioning the wheel with its axis upright permitting the wheel to wobble when it has been set spinning, a member having a peripheral graduated scale, said member being carried by-.said mounting means to rotate in unison with the wheel and adapted to betilted with respect thereto, means to engage said member while the wheel is spinning and wobbling to cause said member to run true, said supporting means including an auxiliary means adapted to engage said mounting means to support the wheel for rotation on a horizontal axis, indicating means on said auxiliary supporting means adapted to cooperate with said member when said auxiliary means is engaged with said mounting means, said indicating means including a contact to engage said' member and movable in response to the wobble thereof when the wheel is turned, and a device to automatically maintain said contact out of engagement with said member when said supporting means is being adjusted to position the wheel axis horizontal, said device being manually oper ated to release said contact for engagement with said member after said supporting means has 4 been adjusted to position the wheel axis horito and adapted to contact said wobble plate when said arm is slid on said arbor toward the wheel, a pointer mounted on said arm for oscillation, said pin and pointer being connected for transmitting movement of one to the other, a cam rotatably mounted on said arm, and a counterweight to position said cam in restraining engagement with said pointer when said arbor is moved to horizontal position, said cam being removed from restraining position to free said arm by manually lifting said counterweight.

12. A wheel balancer comprising, a frame, an arbor mounted in said frame for movement about a horizontal axis, a spindle adapted to have a wheel mounted thereon, a bearing on said arbor to support said spindle for rotation and tilting movement when said arbor is in vertical position,

a second bearing slidably mounted on said arbor, and means including a cam on said frame to slide said second bearing into engagement with said spindle when said arbor is moved to horizontal position to confine said spindle to rotation.

13. A wheel balancer comprising, a frame, an arbor mounted in said frame for movement about a horizontal axis, a spindle adapted to have a wheel mounted thereon, a bearing on said arbor to support said spindle for rotation and tilting movement when said arbor is in vertical position, a second bearing slidably mounted on said arbor, spring means urging said second bearing out of engagement with said spindle, and means including cam means fixed on said frame to slide said second bearing into engagement with said spindle when said arbor is moved to horizontal position to confine said spindle to rotation.

14. A wheel balancer comprising a frame, means adapted to have a wheel mounted thereon for testing, means to support said mounting means, said supporting means being adjustable in said frame to position the wheel with its axis upright or horizontal, said supporting means when positioning the wheel with its axis upright permitting the wheel to wobble when it has been set spinning, a wobble plate carried by said mounting means to rotate in unison with the wheel and adapted to be tilted with respect thereto, means to engage said wobble plate when the wheel is spinning with its axis upright to cause said wobble plate to run true, said engaging means being mounted on said frame and being engageable with said wobble plate only when said supporting means is adjusted to position the wheel with its axis upright, and means operable only when said supporting means is adjusted to position the wheel with its axis horizontal for indicating the adjustment of said wobble plate relative to said mounting means.

15. In a wheel balancer, a vertically disposed arbor, means for supporting a wheel for free rotation and universal tilting movement on said arbor, whereby unbalance of the wheel will cause wobbling thereof, a wobble plate rotatable with the wheel and tiltable with respect to the axis of the wheel, a pair of rollers engageable with the plate for shifting the same until it runs true, means for movably mounting said rollers coaxially disposed with respect to each other and with their common axis offset with respect to the vertical axis of the arbor, and means for limiting the movement of said rollers into predetermined contact with said plate.

16. A wheel balancer comprising a frame, a support rotatable about a horizontal axis on said frame, means located on one side of said axis for mounting a wheel for rotation on said support, spring actuated counterbalancing means intermediate the support and said frame on the opposite side of said axis for automatically positioning said support in an inclined position intermediate the vertical and horizontal positions thereof on said axis to facilitate mounting a wheel on said wheel mounting means.

17. In a wheel balancer a frame, a support on said frame and movable about a horizontal axis, means on one side (if said axis for supporting a wheel for rotation on said support, a linkage mechanism pivotally mounted on the support on the other side of said axis, and resilient means interposed between the frame and linkage mechanism and cooperating therewith for cushioning the movement of the support to horizontal positions.

18. In a wheel balancer a frame, an arbor pivotally mounted on said frame for movement to vertical and horizontal positions, means on one end of said arbor for supporting a wheel for rotation, a linkage mechanism pivotally mounted on the other end of said arbor, and a spring interposed between said frame and linkage mechanism and cooperating therewith for cushioning the movement of said arbor to the horizontal position.

19. In a wheel balancer a frame, an arbor pivotally mounted on said frame for movement to vertical and horizontal positions, means on one end of said arbor for supporting a wheel for rotation, a linkage mechanism pivotally mounted on the other end of said arbor, a spring interposed be- I tween said frame and linkage mechanism and cooperating therewith for cushioning the movement of said arbor to the horizontal position, and a latch associated with said arbor and frame for restraining the arbor against movement of the wheel supporting end thereof below its horizontal position and for automatically locking said arbor when the wheel supporting end thereof is in vertical position.

20. In a wheel balancer a frame, an arbor pivotally mounted on said frame for movement to vertical and horizontal positions, means on one end of said arbor for supporting a wheel for rotation, a linkage mechanism pivotally mounted on the other end of said arbor, a spring interposed between said frame and linkage mechanism and cooperating therewith for cushioning the movement of said arbor to the horizontal position, a latch associated with said arbor and frame for restraining the arbor against movement of the wheel supporting end thereof below its horizontal position and for automatically locking said arbor when the wheel supporting end thereof is in vertical position, and meansfor unlocking said latch.

21. A wheel balancer comprising a frame, an arbor on said frame and movable to vertical and horizontal positions, a wheel support rotatably mounted and universally tiltable on said arbor, and means for automatically locking the wheel support against tilting movement upon movement of the arbor to horizontal position.

22. A wheel balancer comprising a frame, an arbor on said frame and movable to vertical and horizontal positions, a wheel support rotatably mounted and universally tiltable on said arbor, means for automatically locking the wheel support against tilting movement upon movement of the arbor to horizontal position, and means for holding said arbor in either position.

23. A wheel balancer comprising a frame, an arbor on said frame movable to vertical and horizontal positions, a wheel support rotatably mounted and universally tiltable on said arbor, means for automatically locking the wheel support against tilting movement upon movement of the arbor to horizontal position, and means for automatically unlocking said wheel support upon movement of the arbor to vertical position.

24. A wheel balancer comprising a frame, an arbor on said frame movable to vertical and horizontal positions, means for holding said arbor in either position, a wheel support rotatably mounted and universally tiltable on said arbor, means for automatically locking the wheel support against tilting movement upon movement of the arbor to horizontal position, and means for automatically unlocking said wheel support upon movement of the arbor to vertical position.

HERBERT G. HOLMES. 

